In certain industries and/or applications, separating a material from another material is often desired and/or required. Further, the separation of solids and fluids is generally known in a variety of industries and/or applications. For example, industrial separators use screens to separate solids and/or fluids. Also, the mining industry has many applications in which solids may be separated from fluids to extract a desired ore and/or metal during mining processes. Moreover, in the petroleum and/or oilfield operations industries, on-shore and/or off-shore drilling applications use various methods and/or equipment to separate solids from fluids in drilling processes.
Conventional vibratory screen apparatus for sifting material generally use screens with either a hook-strip or a pre-tensioned design. Hook-strip screens generally have a single layer of mesh or multiple layers of mesh bonded together. The screens may be tensioned after the screens are mounted in a basket associated with the vibratory screen apparatus. Opposite sides of the screen are fitted with a hook-strip formed by a turn-back element. The hook-strip may be hooked around and/or attached on a tension rail which may be attached to the side wall of the basket. A tension bolt may be used to secure the hook-strip. Other loading means to apply tensioning and securing forces to secure the hook-strip may be used. Tightening the tension bolt may move the tension rail outwardly towards the walls of the basket to apply and/or transfer tension to the screen.
Hook-strip screens may be pre-tensioned prior to mounting in the basket by attachment of the screen mesh element to an apertured support plate, typically by an adhesive. A screen having a plurality of mesh layers may be pre-tensioned. In some designs, multiple integrated mesh layers may be corrugated prior to mounting to an apertured support plate associated with the basket. Hooks may be engaged with corresponding eyelets on the apertured support plate to form the mesh-plate combination.
Hook-strip screens may be relatively complex and require substantial skill to assemble and/or to prepare for use. Mounting of screen members on the basket may result in significant downtime of the vibratory screen apparatus and also involve the use of multiple parts. Configuring the basket and/or hook-strip screen to attain a desirable screen tension to process incoming sieved material may involve fine tuning.
Further, the hook-strip screen may be damaged if excessive force is applied when tightening attachment bolts, screws, connectors and/or the like to tension the hook-strip screen. In addition, irregularities in the hook-strip screen, attachment bolts and/or the like may cause poor sealing between the hook-strip screen and the basket. For instance, a metal on a metal seal may cause leakage. Unscreened material may pass through gaps between the screen and the basket and may mix with and/or pollute screened material below a filtration mesh of the hook-strip screen. Attempts to overcome the poor seal by placing rubber strips and/or gaskets at metal/metal interfaces may require intricate and time-consuming fitting procedures. The rubber strips and/or gaskets frequently loosen during vibration and may become lost or lodged in the vibratory apparatus to obstruct and/or otherwise damage the machinery. In addition, applying tension to the screen when tightening the tension bolt may add undesirable stress to the machine frame.
Pre-tensioned screens may have one or more layers of mesh permanently bound under tension to a rigid steel and/or plastic apertured plate support frame. The mesh screen may be flat or crowned. The mesh screen and support frame are inserted into the basket as a unit which requires no adjustment to the tension of the screen. The mesh screen and the support frame are normally secured in the machine by clamps from above and/or below. The clamps may be hydraulic pistons, inflatable clamping bags, bolts, tapered elements and/or the like.
Conventional pre-tensioned screen units with integrated support frames may be bulky, heavy and difficult to handle, transport and/or store. Typically, the design of such screen units may be complex, and the frames may be expensive to construct. Plastic injection molding is commonly used which is an inflexible method of construction. The frames utilize large amounts of material which require disposal when the screen units are replaced. The disposal may be inconvenient, expensive and/or may negatively impact the environment.
Over the life of the screen, the particles cause wear on the wire mesh. Damage causes a breach in the mesh. As a result, the area of the mesh allows larger particles to pass through than desired. After the damage occurs, the screen must be replaced or repaired.
Many conventional screens may be large and cumbersome to handle during transportation, installation and/or removal. Handling and/or manipulating the screens is difficult for a single user. The screens may be relatively large in size and may also be rigid, both of which increase the difficulty in removing the screen from the vibratory separator.
Also, the rigid screens are difficult to transport and/or store. In certain situations in which the available space surrounding the separator is limited, maneuvering the screens for installation and/or replacement is challenging.
A need exists for a screen to allow the screen to fold, roll and/or coil without causing a permanent raised crease. The reduced size screen may be more easily carried and/or transported.